Method of polymerizing hydrocarbons



Sept. 19, 1950 c. F. VAN BERG 2,523,158

METHOD OF POLYMERIZING HYDROCARBONS Filed Nov. 9, 1946 FIG. 2.

Unreucted Feed Stock Reactor Flush Tank n and Tertiary Olefin Onto lysi FIG. I.

ATTORNEY.

Patented Sept. 19, 1 950 I TAT METHOD OF POLYMERIZIN G :CharlesF. Van

HYDnooAnBoNs f Berg, Goose Creek, Tex., assignor,

by mesne assignments, to Standard Oil Devel v opment Company, Elizabeth, N., J., a corporal 'j tionof Delaware I npplicationNovember 9, 1946,.Seria1No. 709,004

2 Claims. (Cl. 260-853) present invention is directed to'an improvement ina method forfconducting polymeriza'tions or condensations inwhich liquid mate- -ri a1sa're'convertedintb plastic and/or elastic solids or semi-solids. More particularly, the in vention relates to the production of synthetic stream at a plurality of points additionalfe'ed rubber from low boiling hydrocarbons.

carbon simultaneously at a plurality of points in the reaction zone/i In the preferredmodifica'tion T In order to illustrate the nature of the present inve'rition', reference willbe made in the following discussionto the particular process in which isobutylene'is copolyme'rized with a diolefin in the. presence of a metal halide catalyst. Infpraor tice, this process is carried out in a reactor in which a reactionfrnass is circulated and into which reactants and catalyst are injected. In

order to keep .theliquid in circulation an agitator I y is provided in the vessel.

Prior to the present'inventionit has .been genral practice t conduct the polymerization of tertiary olefins, and diolefins in the presence'of diluent liquid; specifically an alkyl halide such as rn'ethyl halide has been found particularly suitable; The reaction is catalyzed by the action of a catalytic mat'erial suchas an aluminum halide dissolved in asuitable solvent, and it is customary to empl'oy temperatures of the order of 120 to about 175 F.' to form polymers of the proper molecular weight having rubbery characteristics. Goodoperation is obtained at temperatures betWeen'%'130 and ,145 F.

Since considerable heat of reaction is liberated in the polymerization of tertiary olefins and diolefins in the! aforementioned type of reaction, it is necessary to refrigerate the reaction material to maintain the low temperatures required. One

method of providing refrigeration is to employv internal refrigeration with a suitable refrigerant concentrations and/or catalyst concentration. A sticky low molecular weight material is thus produced and is believed to be the origin of agglomerate's which eventually plug the outlet lines.

Temperature effects attendinglocalized reactions,

suchfas that occurring at high reactant concentrations encountered at or near the feed injection points, aggravate the reaction rate and produce an additive accelerating effect which may give rise to the agglomerates mentioned above. Thus,

it is believed that by reducing the extent .of

included with the material charged to the re-' the feed hydrocarbon is injected at a plurality of points spaced along the reaction zone. Thus, in effect, a circulating streaam of hydrocarboriis established to which catalyst is added and to this" hydrocarbon isadded. By virtue of the present invention concentrations of the reactantfhydrocarbons at a given point in the circulating stream are maintained at a point where localized reactions do not take place by excessivetemperature r1ses.

' It is contemplated that a plurality of feedin- J'ection points may be established'in areaction zone in which the liquid feed stock is circulated; While as few as'4 injection points may be em ployed, as many as 12 or'more may be satisfa'c' torily provided.

The invention (may be better understood by reference to the following detailed descriptibno'i the accompanying drawing in which Fig. 1 is a front'elevation of a preferredem bcdiment; and e l T Fig. 2 is a section taken across line lllI of one portion of the apparatus. v

Turning now to the drawing and specifically to Fig. l, numeral ll designates a reaction zone and numeral l2 designates a fiashtank which is connected to reaction zone I l by way of line 13; Reaction zone II is provided with a mixing means l4 actuated by a prime mover [5 connecting to the mixing means I by shaft l6. Reaction zone ll is provided with a jacket ll into which a suitable refrigerant may be injected by way of line I8 and then withdrawn by line 18a. Reaction zone H is provided with an. annulus H! for circulation of the reactant liquids;

A hydrocarbon feed comprising a mixture of isobutylene and isoprene and a diluentfsuch as an alkyl halide,- methyl chloride, for example-is introduced into the system by way of line 20- which is manifolded into feed dispersing rings 2| controlled respectively by valves 22, 23 and 24. Feed dispersing rings 2| terminate in reaction zone H in injection nozzles 25 by way'of which rin'gas' a result'of high temperatures, reactant reactant concentration at a given point a reduction of mass fouling is accomplished. According to the present invention, this difficulty'is overcome by introducing the feed hydro.

the hydrocarbon reactants are dispersed through out the reaction zone. i

As mentioned before, reaction zone H and flash tank l2 are fluidly connected by line l3-by way of which reaction products are removed-from the zone lltothe flashtank l2.

As the hydrocarbons are injected into the reaction zone II at a low'temperature, in the neighborhoodof 20 to 1'75 F.,-a chilled solution of aluminum chloride in methyl chloride, for example, is introduced by way of line M. A polymerization reaction is induced in the presence of a catalyst and the material in there-action zone ll circulates upwardly through theannulus l9 and then downwardlyand upwardly agaimcreating a' circulating stream. -Sinc'e' hy-' ously through line 13 where it has added to it hotwater at a temperature of about 160 F. by Way of line 21.

The slurry of hot water and polymerized'prod- V ucts is introduced into the i' lash' tank :12 which is similar to reaction zone I l -andis-provided with a mixing means 28 actuated by'a prime mover 29 through shaft 30.

Unreacted hydrocarbons :and alkyl halide diluent are removed from the flash tank 42 :by line 3i while a slurry of the hydrocarbon polymer in hot water is withdrawn by line 32.

Steam may be introduced into the flash 'tan'k through line 33 to maintain the temperature at the desired figure. As mentioned before, hot water in-line 21 is introduced into line 1'3 to quench the reactioniprod'uct. "This hot water is withdrawn-from "the'bottom of flash tank 32 by line 34 and pump 35.

It is contemplated that therewill be added to fiashtank l2 suitable wetting agents, inhibitors and various other processing "aids which maybe required in later steps ofprocessing the polymer. 'Whiletherefrigerated diluentinjected into'the reaction zone has been described as an alkyl halide, other diluents, such *as carbon disulfide, which will not freeze at the low temperatures employed in the reaction and which do not interfere'with the reaction, maybe used.

Particular reference has been .had to polymerization of tertiary olefins and diolefins merely for the -purpose of illustration. The technique "herein described is applicable to any reaction of this general typein which liquid .rea'c'tants are employed and a plastic or rubbery solid or semisolid is produced.

The invention w'illbe further illustrated by the following examples:

Examples A number of runsin a commercial unit were performed in which a mixture comprising approximately 0.5% isoprene, 126.5% isobutylene, and 73% methyl chloride was polymerized in the presence of a catalyst solution of: 0.3 weight per cent of aluminum chloride in methyl chloride at a temperature in the range between 'l 25-and -140 F. Apparatus similar to that described in the drawing was employed for all of the runs. In a, first series of runs conventional-conditions were simulated; -a--single injectionupoint .for the given the ifeed ratios and catalyst :solution concentration may be varied widely. In the specific instance given, a mixture containing 0.5% isoprene, 26.5% isobutylene, and 73% methyl chloride was employed as the feed mixture. However, the hydrocarbon component of the feed "may vary between about 22% and Similarly, while a catalyst solution of 0.3% aluminum chloride in methyl chloride was employed, the catalyst solution may vary between 0.1% and 0.4% by-weight o'f aluminum chloride in methyl chloride.

In the drawing the .dispersing rings 2| are shown to terminate in four injection nozzles. It is within the scope and spirit of the present 'invention that a larger or smaller number of injection nozzles may be employed and similarly a larger or smaller number of dispersing rings may be used.

It is contemplated that the hydrocarbon .introduced through dispersing rings '2! controlled by valves 22, 23, and 2 1 will be introduced in equal amounts. Under some circumstances, it may be desirable to introduce larger amounts of hydrocarbon feed through one of the dispersing rings and smaller amounts through other-of the dispersing rings.

The nature and object of the present invention having been fully described'and illustrated,

what is claimed as new and useful and is desired to be secured by Letters Patent is:

1. A continuous method for polymerizing isobutylene and isoprene at .a temperature in the tinuously introducing a mixture containing Iisobutylene and .isoprene in'the weight ratio ojf. 5'3

parts .of 'isobutylene t0 .1 part .of .isoprene Chilled to a temperature in the range of -120 to 1Z5 F. into said agitated mixture at a plurali-ty of points spaced along ,said reactor and continuously recovering a polymer from said hydrocarbon feed mixture was employed, the

feed entering into the reactor vessel-l l at a point opposite the catalyst injection line. 2%. In a second -ser-ies of runs the hydrocarbon feed-.mixture injected into the reaction vessel at .a .plurality of points, said points corresponding to the injection nozzles 25 in the reactor vessel H. In the first seriesof runs, runs of .-15.-8, 10.5, 8.5, 24.1, 25.6, and 47 hours duration were obtained while producing a butyl rubber of commercial agitated mixture.

.2. Amethod .for continuously olymerizing iisobutylene and isoprene at a temperature in the range of 120 F..to .1.'Z5 the presence of a Friedel-Crafts .catalysit which comprises the steps or" establishing a chilled .circulating stream of a mixture containingdsobu'tylene andisoprene in the weight .ratio of 53..par'.ts o'f'isobutylene to 1 part of isoprene, continuously introducing a chilled solution .of a Eriedel-Crafts catalyst into the circulating stream, continuously introducing a chilled mixture containing .isobutylene and isoprene .in'the weight ratio of .53 parts of isobutylene to 1 part of ,isoprene .simliltaneonslyat .a

5 plurality of points in said .chilled circulating stream and continuously recovering .a polymer from the chilled .circulatingstream.

. CHARLESVANBERG.

REFERENCES CITED The following references'are of record in the file of this patent:

Number 

1. A CONTINUOUS METHOD FOR POLYMERIZING ISOBUTYLENE AND ISOPRENE AT A TEMPERATURE IN THE RANGE OF -120*F. TO -175*F. IN THE PRESENCE OF ALUMINUM CHLORIDE WHICH COMPRISES THE STEPS OF ESTABLISHING IN A REACTION VESSEL AN AGITATED MIXTURE CONTAINING ISOBUTYLENE AND ISOPRENE IN A WEIGHT RATIO OF 53 PARTS OF ISOBYTYLENE TO 1 PART OF ISOPRENE, CONTINUOUSLY INTRODUCING A SOLUTION OF ALUMINUM CHLORIDE IN METHYL CHLORIDE CHILLED TO A TEMPERATURE IN THE RANGE OF -120*F. TO -175* F. INTO THE AGITATED MIXTURE IN THE REACTOR, CONTINOUSLY INTRODUCING A MIXTURE CONTAINING ISOBYTYLENE AND ISOPRENE IN THE WEIGHT RATIO OF 53 PARTS OF ISOBUTYLENE TO 1 PART OF ISOPRENE CHILLED TO A TEMPERATURE IN THE RANGE OF -120*F. TO -175*F. INTO SAID AGITATED MIXTURE AT A PLURALITY OF POINTS SPACED ALONG SAID REACTOR AND CONTINUOUSLY RECOVERING A POLYMER FROM SAID AGITATED MIXTURE. 